1. Field
The field generally relates to an organic light-emitting display (OLED) device and a method of manufacturing the same, and more particularly, to an OLED device including a thin-film transistor (TFT) and a method of manufacturing the OLED device.
2. Description of the Related Technology
Each pixel of an active matrix organic light-emitting display (AMOLED) device includes a thin-film transistor (TFT) and an organic light-emitting element.
An active layer of the TFT has been formed using amorphous silicon or poly-silicon. Some active layers have been formed using an oxide semiconductor.
Characteristics of oxide semiconductors, such as a threshold voltage and S-factor, are prone to variation when exposed to moisture or oxygen permeating from outside the organic light-emitting device. The oxide semiconductor threshold voltage is prone to further variation due to the DC bias of a gate electrode during the operation of a TFT. Therefore, the stability of the DC bias becomes an important factor when using an oxide semiconductor for forming the active layer of a TFT in an organic light-emitting display device.
Some devices have applied a film formed of AlOx or TiN to the substrate, in order to strengthen the barrier characteristics of the oxide semiconductor with respect to moisture or oxygen. However, such films are generally formed by reactive sputtering or active layer deposition (ALD), and are thus difficult to apply large substrates. This difficulty affects the ability to mass-produce TFTs.